title: Validation of a new homogeneous immunoassay for the detection of carisoprodol in urine.
abstract: The objective of this project was to validate a new high-throughput homogeneous enzyme immunoassay (HEIA) for the rapid detection of carisoprodol in human urine. Carisoprodol (Soma(®)) and meprobamate are widely prescribed as musculoskeletal pain relief drugs and are listed as one of the 10 most frequently identified drugs associated with DUI cases. Carisoprodol has a short elimination half-life of 1-3 h; however, its major active metabolite, meprobamate, has a longer elimination half-life of 6-17 h. As a result, it is important for an immunoassay to cross-react with both compounds. The advantage of this new assay is that cutoff concentrations can be adjusted between 100 and 500 ng/mL. The reportable range was 25 to 1000 ng/mL for carisoprodol and 50 to 10,000 ng/mL for meprobamate. The intraday coefficient of variation (% CV) for the semi-quantitative assay was less than 1%. The homogeneous assay was validated with a total of 86 urine samples previously analyzed by liquid chromatography-tandem mass spectrometry with carisoprodol concentrations ranging from 50 to 10,000 ng/mL. The accuracy was found to be 100% when immunoassay cutoff concentrations of carisoprodol and meprobamate were set at 100 and 1000 ng/mL, respectively.
authors.affiliation: Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767, USA. gwang@immunalysis.com
authors.forename: Guohong
authors.initials: G
authors.lastname: Wang
authors.forename: Kim
authors.initials: K
authors.lastname: Huynh
authors.forename: Rekha
authors.initials: R
authors.lastname: Barhate
authors.forename: Warren
authors.initials: W
authors.lastname: Rodrigues
authors.forename: Christine
authors.initials: C
authors.lastname: Moore
authors.forename: Cynthia
authors.initials: C
authors.lastname: Coulter
authors.forename: Michael
authors.initials: M
authors.lastname: Vincent
authors.forename: James
authors.initials: J
authors.lastname: Soares
mesh_terms: D002328:Carisoprodol / Q000737:chemistry / Q000652:urine*; D006207:Half-Life; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008620:Meprobamate / Q000652:urine; D009125:Muscle Relaxants, Central / Q000737:chemistry / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D009125:Muscle Relaxants, Central; D002328:Carisoprodol; D008620:Meprobamate